Inverter failure is very similar to the backlight lamp failure. the screen gets very dark and the image on the screen becomes very faint, barely visible under a bright light. LST01 is a custom build tester for Laptop screen repair it can help you to isolate the problem between CCFL Backlight Lamp and Inverter in seconds. It is a Must-Have-It tool for people who offer laptop computer repair service. Save Time! Save Money!